Nitrofurantoin
InfectionsAlso known as Macrobid
Nitrofurantoin concentrates in your urine, which makes it great at clearing bladder infections — and only bladder infections. It doesn't reach high enough levels elsewhere in the body to treat kidney infections or anything else. Take it with food so it absorbs better and sits easier on your stomach. And a heads-up: it can turn your urine dark yellow or brown, which is completely harmless.
How to take it
When
Space doses evenly, exactly as prescribed.
Food
Always take it with food — it absorbs better and is gentler on your stomach.
Avoid
Don't take antacids containing magnesium trisilicate — they interfere with the drug.
Good to know
Dark yellow or brown urine is a harmless side effect, not a warning sign.
Missed a dose?
Take it as soon as you remember, with a bite of food. If it's almost time for your next dose, skip the missed one. Never double up.
Common side effects
- Nausea or upset stomach
- Headache
- Harmless brown or dark yellow urine
- Gas or loss of appetite
Call a doctor if
- A new cough, shortness of breath, chest tightness, or fever — this drug can rarely inflame the lungs. Call your doctor now.
- Tingling, numbness, or burning in your feet or hands — possible nerve damage. Call your doctor right away.
- Trouble breathing, swelling of the face or throat, or hives — serious allergic reaction. Get emergency help now.
- Yellowing of the skin or eyes, or dark urine that comes with fatigue and belly pain — possible liver trouble.
- Severe watery or bloody diarrhea, during treatment or even weeks after — possible C. diff gut infection. Call your doctor; don't just take anti-diarrhea medicine.